@LorraineP : I will happy to share comments on this.
Data nodes can be increased by configuring value.yaml at the time of helm chart installation.
dataNodes: 3
( timescaledb-kubernetes/values.yaml at master · timescale/timescaledb-kubernetes (github.com).
Here the current limitations\features such as adding nodes/removing/reattaching will still applicable.
Refer below discussion on adding/reattching nodes discussion from the post.
( Add new node or reattaching node after creating distributable hype table - TimescaleDB and PostgreSQL - Timescale Community Forum)